/Engine/Source/Runtime/GeometryCore/Public/Spatial/BlockedDenseGrid3.h
reference to a unique pointer that points to a block that may or may not be allocated
const [TUniquePtr](API\Runtime\Core\Templates\TUniquePtr)< [BlockData3Type](API\Runtime\GeometryCore\Spatial\TBasicBlockedDenseGrid3\BlockData3Type) > & GetBlockData ( int32 BlockIndex ) const